A dependent variable is an attribute whose value is determined by the existence of other factors. A variable can be any kind of category or group that is being measured. It can take the form of an idea, object, period, or even feeling. For instance, the score of a test may be considered as dependent variables since they can change based on factors like how well a person studied for the test, the level of rest they had prior to taking the test or even whether they were well fed during the test. A dependent variable is used to identify the relationship between two elements and looks at the factors that influence the way change happens. It is the attribute that is affected and whose change measured in an experiment. Usually, a dependent variable changes in response to an independent variable. The reason why it is known as dependent is because it tends to rely on an independent variable.
An independent variable is the attribute that is not changed by another variable, it usually stands alone. An example of an independent variable is the age of a person. This is because age is not influenced by factors such as what one eats, how well they attend school or watch television. When looking out for the relationship that exists between variables, one tries to find out whether an independent variable has any kind of influence in the change that happens in or on a dependent variable. A scientific experiment cannot have a dependent variable and lack an independent variable. For instance, in measuring the effect of stress on a person’s heart beat rate, stress would be used as an independent variable while the heart beat rate would serve as the dependent variable. Stress levels can be manipulated directly as the change in heart beat rate is monitored or measured.